Filters, Filter Assemblies, Filter Systems and Methods for Identifying Installation of Qualified Filter Elements

ABSTRACT

A filter assembly has a qualified filter element that filters fuel, o filter housing for the qualified filter element and a water-in-fuel sensor that senses presence of water in the filter housing. An electrical resistance of the water-in-fuel sensor changes based upon whether the qualified filter element is installed in the housing. A filter assembly can also have a plurality of magnetic elements disposed on at least one of the filter housing and the qualified filter element. A plurality of wires are disposed on at least the other of the filter housing and the qualified filter element. The control circuit determines that the qualified filter element is installed in the filter housing based on a change in the electrical current in the plurality of wires.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of and priority to U.S.Provisional Patent Application Ser. No. 61/640,420, filed Apr. 30, 2012,which is incorporated herein by reference in entirety.

FIELD

The present disclosure relates to filters, and more particularly tofilters, assemblies, systems and methods for identifying installation ofqualified filter elements.

BACKGROUND

U.S. Pat. No. 6533,926, which is incorporated herein by reference inentirety, discloses a replaceable filter cartridge that includes an endplate having a data component electrically coupled to a pair ofconcentric circuit rings. The data component may include a sensor, datachip, or resistor and is configured to provide filtration information toa remote station when the filter cartridge is positioned within thehousing of a filtration assembly such that the circuit rings connectwith electrical contacts in the housing,

U.S. Pat. No. 6,537,444, which is incorporated herein by reference inentirety, discloses a replaceable filter cartridge that includes afilter element and an end plate bonded to an end thereof. The end plateincludes at least two electrical contacts and a key way that includes arelief section. Upon proper installation of the filter cartridge intothe housing of a filter assembly, a key attached to a centerpost of thehousing is received in the relief section of the end plate and theelectrical contacts thereof make contact with corresponding electricalcontacts in the housing causing a data component to be energized. Thedata component may include a sensor, data chip, or resistor assembled toan exposed surface of the endplate.

U.S. Pat. Nos. 7,615,151 and 7,850,845, which are incorporated herein byreference in entirety, disclose filters with installation integrity thatpermit fluid flow only in a first installation condition and not in asecond undesired or mis-installation condition, including improperalignment or mounting of a filter element in a housing, an incorrectreplacement filter element, absence of a filter element, and anincorrect housing cover. A magnetically actuated valve has a pistoncontrolling fluid flow according to installation condition.

U.S. patent application Ser. No. 13/092,310, which is incorporatedherein by reference in entirety, discloses a water sensor for a fuelfiltration apparatus that includes a main body with at least oneelectrical contact disposed proximate the first end of the main body.The electrical contact(s) is operatively connectable to an electroniccontrol unit. Multiple sensor contacts are disposed proximate a secondend of the main body. The sensor contacts are configured to detectmultiple water levels and provide an output on each water leveldetected. The electrical contact is configured to send the output to anelectronic control unit. The water level information provided by thewater sensor can be tracked by a control device to determine if the fillrate of water meets an alarm value.

U.S. Patent Application No. 61/355,401, which is incorporated herein byreference in entirety, discloses a run-safe filter system for confirminginstallation of a qualified filter element in a housing. An electricalswitch has a first electrical condition in response to a qualifiedfilter element being installed in the housing, and a second electricalcondition in response to the absence of a qualified filter elementinstalled in the housing.

SUMMARY

This Summary is provided to introduce a selection of concepts that arefurther described herein below in the Detailed Description. This Summaryis not intended to identify key or essential features of the claimedsubject matter, nor is it intended to be used as an aid in limiting thescope of the claimed subject matter.

In some examples, filter assemblies comprise a qualified filter elementthat filters fuel, a filter housing for the qualified filter element,and a water-in-fuel sensor that senses presence of water in the filterhousing. The assemblies are configured such that an electricalresistance of the water-in-fuel sensor changes based upon whether thequalified filter element is installed in the housing.

In other examples, filter systems comprise a qualified filter elementthat filters fuel, a filter housing for the qualified filter element, awater-in-fuel sensor that senses presence of water in the filterhousing, and a control circuit that determines whether there is water inthe filter housing based upon an electrical resistance of thewater-in-fuel sensor. The control circuit is electrically connected tothe water-in-fuel sensor and determines whether the qualified filterelement is installed in the housing based upon the electrical resistanceof the water-in-fuel sensor.

In further examples, methods are fir identifying a qualified filterelement in a filter assembly having a filter housing. The methodscomprise: providing a water-in-fuel sensor having an electrical circuitcomprising a first portion located with the housing and a second portionlocated with the qualified filter element, inserting the qualifiedfilter element into the filter housing, sensing with a control circuit achange in electrical resistance of the water-in-fuel sensor, andindicating that the qualified filter element is installed in the filterhousing based on the change in electrical resistance.

In further examples, filter assemblies comprise a filter housing, aqualified filter element, and a plurality of magnetic elements on atleast one of the filter housing and the qualified filter element. Eachmagnet in the plurality of magnetic elements has a magnetic field. Aplurality of wires is disposed on at least the other of the filterhousing and the qualified filter element. A control circuit iselectrically coupled to the plurality of wires and detects an electricalcurrent in the plurality of wires. When the qualified filter element isinstalled in the filter housing, the plurality of wires cuts themagnetic field of at least one of the plurality of magnetic elements andthereby changes the electrical current in the plurality of wires. Thecontrol circuit determines that the qualified filter element isinstalled in the filter housing based on a change in the electricalcurrent in the plurality of wires.

In further examples, methods are for identifying a qualified filterelement in a filter assembly having a filter housing. The methodscomprise: providing a plurality of magnetic elements on at least one ofthe qualified filter element and the filter housing, the plurality ofmagnetic elements comprising a magnetic field; providing a plurality ofwires on at least the other of the qualified filter element and thefilter housing; installing the qualified filter element into the filterhousing; sensing with a control circuit an electrical current along theplurality of wires; and identifying with the control circuit that thequalified filter element is installed in the filter housing when theelectrical current across the wires changes.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of filters, assemblies, systems and methods for identifyinginstallation of qualified filter elements in a filter housing aredescribed with reference to the following figures. Like numbers are usedthroughout the figures to reference similar features and components.

FIG. 1 depicts a filter system for filtering fuel.

FIG. 2 is a partial view of a filter assembly shown FIG. 1, showing awater-in-fuel sensor.

FIG. 3A is another example of a water-in-fuel sensor for the filterassembly.

FIG. 3B is another example of a water-in-fuel sensor for the filterassembly.

FIG. 4 is another example of a water-in-fuel sensor for the filterassembly.

FIGS. 5A-5B are examples of an end cap on a filter housing of theassembly.

FIGS. 6A-6B are further examples of an end cap on a filter housing ofthe assembly.

FIGS. 7A-7D are examples of water-in-fuel sensors and end capcombinations.

FIGS. 8A-8B are further examples of water-in-fuel sensors and end capcombinations.

FIGS. 9A.-9F are examples of locking arrangements for water-in-fuelsensors and end cap combinations.

FIGS. 10A-10B are examples of mechanical locks for locking first orsecond portions of the electrical circuit with respect to each other.

FIGS. 11A-11D are examples of filter assemblies having a plurality ofmagnetic elements, a plurality of wires, and a control circuit that iselectrically coupled to the wires and monitors a current in the wires.

DETAILED DESCRIPTION

In the present Detailed Description, certain terms have been used forbrevity, clearness and understanding. No unnecessary limitations are tobe inferred therefrom beyond the requirement of the prior art becausesuch terms are used for descriptive purposes only and are intended to bebroadly construed. The different filters, assemblies, systems andmethods described herein may be used alone or in combination with otherfilters, assemblies, systems and methods. Various equivalents,alternatives, and modifications are possible within the scope of theappended claims.

FIG. 1 depicts a filter system 20 for filtering fuel. The filter system20 includes a filter assembly 22 having a replaceable, qualified filterelement 24 that is contained in a reusable filter housing 26. The shapesand configurations of the qualified filter element 24 and filter housing26 are merely exemplary can widely vary from that which is shown anddescribed. That is, the concepts of the present disclosure can beapplied to a wide variety of filtration systems and assemblies. In theparticular example shown, the qualified filter element 24 is acylindrical cartridge that is installed into a correspondinglycylindrical reusable filter housing 26. The qualified filter element 24has top and bottom end caps 28, 30 and a pleated filter media 32 isdisposed therebetween. The filter housing 26 has abuse receptacle 34with a lower end wall 36 and upwardly extending circumferentialsidewalls 38. The lower end wall 36 and upwardly extendingcircumferential sidewalk 38 together define a cavity 37 for receivingand housing the qualified filter element 24. A cover 40 is removablyconnectable to the top of the circumferential sidewalk 38 via a threadedconnection 42. Attachment of the cover 40 closes the cavity 37 andsecures the qualified filter element 24 in place. In this example, thebase receptacle 34 also has a centerpost 44 that extends into an innercircumferential aperture 43 in the qualified filter element 24. In someexamples, an upper end (not shown) of the centerpost 44 can connect toor abut a lower surface (not shown) of the top end cap 28, as isconventional. As is conventional, fuel that flows through the filterassembly 22 flows through the filter media 32 for filtering impuritiestherefrom.

Referring to FIGS. 1 and 2, the filter assembly 22 also includes aunique water-in-fuel (hereinafter “WIF”) sensor 46 that is configured tosense a presence of water in the filter housing 26. Water that occurs infuel filter housings can adversely affect performance of the filterassembly and therefore it is desired to diagnose a water condition infuel filter housings as soon as it occurs. In this example, the WIFsensor 46 is configured to advantageously detect when a certain level ofwater accumulates at the bottom of the base receptacle 34 so that anoperator can be alerted to the situation and take corrective action. Thebasic functionality of a WIF sensor is well known by those havingordinary skill in the art. Examples of conventional WIF sensors areprovided in the applicant's U.S. Patent Application Publication No.2011/0259802, which is incorporated herein by reference. WIF sensorsoperate based upon the principle that fuel has a very low conductivity,and for all practical purposes, can be considered an electricalinsulator. Water, on the other hand, is relatively conductive due to theimpurities in the water. Conventional WIF sensors have an electricalcircuit (hereinafter a “WIF circuit”) that receives an electricalcurrent. The WIF circuit provides a resistance to the electricalcurrent. The amount of resistance will vary depending upon whether aportion of the sensor is disposed in water or fuel. Based on theseprinciples, WIF sensors allow an operator can readily diagnose whetherthere is water in the fuel by monitoring the level of resistance in thesensor.

The unique WIF sensor 46 shown in FIGS. 1 and 2 differs fromconventional WIF sensors in that it includes an electrical circuit(hereinafter “WIF circuit”) 48 having a first portion 49 that is locatedwith the filter housing 26 and a second portion 51 that is located withthe qualified filter element 24. The discrete first and second portions49, 51 are oriented such that proper installation of the qualifiedfilter element 24 in the filter housing 26 electrically connects thefirst and second portions 49, 51 and thereby provides a more completeWIF circuit 48 of the WIF sensor 46 and modifies the electricalresistance of the first portion 49. As will be explained further hereinbelow, separating the WIF sensor 46 into discrete portions thatrespectively are disposed on the qualified filter element 24 and on thefilter housing 26 provides improved filter systems 20, filter assemblies22 and methods of use that readily allow an operator to identify whetheror not a filter element that is installed into the filter housing 26 isa qualified filter element 24, as opposed to a counterfeit or any othernon-conforming filter element. Installation of a qualified filterclement 24 actively, electrically connects the first and secondportions, 49, 51, thereby changing the resistance of the WIF circuit 48,and thereby indicating that the qualified filter element 24 has beeninstalled. The exact nature and configuration of the noted first andsecond portions 49, 51 can vary from that which is shown in FIGS. 1 and2, as is evident from the examples discussed herein below with referenceto the remaining Figures. Also the WIF sensor 46 does not need to belocated at the bottom of the base receptacle 34 and depending upon theorientation of the filter housing 26 and fluid flow therethrough, theWIF sensor 46 can instead he located to diagnose water conditions atother locations in the filter housing 26.

In the particular example shown in FIGS. 1 and 2, the first portion 49of the WIF circuit 48 includes first and second electrical contacts,which in this example are elongated metal pins 60, 62 that extendthrough a body 66 of the WIF sensor 46. Other amounts and types ofelectrical contacts can also or instead be employed, and can alsoinclude plug holes and/or the like. In this example, the WIF sensor 46is installed in the lower end wall 36 and both of the first and secondpins 60, 62 have first ends 68 that extend into the base receptacle 34and second ends 70 that extend out of the base receptacle 34. The firstends 68 are for sensing whether there is water in the filter housing 26and the second ends 70 are for connecting to a control circuit 50, aswill be described further herein below. The second portion Si of the WIFcircuit 48 is located with the qualified filter element 24 and includesconductive material 23 that electrically connects the first ends 68 ofthe pins 60, 62 together when the qualified filter element 24 isproperly installed in the filter housing 26. In this example, theconductive material 23 is located on the bottom end cap 30 of thequalified filter element 24; however the conductive material 23 does nothave to be located at the bottom end cap 30 and instead could be locatedelsewhere on the qualified filter element 24 in any location whereconductive material 23 effectively electrically connects the first ends68 of the first and second pins 60, 62 when the qualified filter element24 is installed in the housing. In this example, the conductive material23 includes any conductive metal; however the nature and configurationof the conductive material 23 can widely vary and differentconfigurations of the conductive material 23 are further describedherein below with reference to FIGS. 5-8.

Referring to FIG. 1, the filter system 20 also includes a controlcircuit 50 that is electrically connected to the WIF sensor 46 byelectrical links 52, 54 extending between the control circuit 50 and thesecond ends 70 of the first and second pins 60, 62. The control circuit50 includes a programmable processor 56 and a memory 58. As isconventional, the programmable processor 56 can be communicativelyconnected to a computer readable medium that includes volatile ornonvolatile memory upon which computer readable medium is stored. Theprogrammable processor 56 can access the computer readable medium andupon executing the computer readable code carries out the functions asdescribed herein. The control circuit 50 can be any suitable controldevice for interpreting information detected by the WIF sensor 46 andcan be, but is not limited to an engine control module (ECM), acontroller, a fluid management control module, or any suitabledata/information processing device, which may employ one or moresoftware routines, as appropriate. In this example, the control circuit50 is powered by any conventional power source, such as for example oneor more batteries 63. Through the electrical links 52, 54, the controlcircuit 50 is configured to supply an electrical current to one of thefirst and second pins 60, 62 extending through the WIF sensor 46 and toreceive electrical current from the other of the first and second pins60, 62. However the control circuit 50 does not have to supplyelectrical current to the pins 60, 62; rather the noted electricalcurrent could be directly provided to the WIF sensor 46 by any otherpower source such a battery. Through the electrical links 52, 54, thecontrol circuit 50 is electrically connected to the WIF sensor 46 suchthat changes in electrical resistances of the WIF sensor 46 are sensedby the control circuit 50. As described further herein below, based uponsuch changes of electrical resistance, the control circuit 50 isprogrammed to identify both whether there is water in the noted fuel andalso whether there is a qualified filter element 24 installed in thefilter housing 26.

The fitter system 20 optionally can include an output device 57 havingwarning lights 59, 61 and/or other conventional means for alerting anoperator as to whether there is water in the filter housing 26 andwhether there is a qualified fitter element 24 installed in the filterhousing 26. The control circuit 50 is electrically connected to theoutput device 57 via a wired or wireless communication link 53 acrosswhich electronic signals can be sent by the control circuit 50 andreceived by the output device 57. The control circuit 50 is programmedto control output device 57 to light the warning lights 59, 61 when thecontrol circuit 50 determines that there is water in the filter housing26 and when the control circuit 50 determines that there is a qualifiedfilter element 24 in the filter housing, respectively. The type ofoutput device 57 can vary from that shown and described, and can forexample include any conventional output means for communicatinginformation to an operator, such as video screens, LED light displays,audio speakers, and/or the like.

In the example shown in FIGS. 1 and 2, the body 66 of the WIF sensor 46is connected to the lower end wall 36 via a threaded connection 64. Thusthe WIF sensor 46 is installed by rotating one of the WIF sensor 46 andfilter housing 26 with respect to the other. However the threadedconnection 64 is just one of many examples of possible permanent ortemporary connections between the WIF sensor 46 and the lower end wall36. In another example shown in FIG. 3B, the body 66 of the WIF sensor46 can be permanently molded as a part of the lower end wall 36, suchthat the WIF sensor 46 is part of the filter housing 26. While the typeof connection of the WIF sensor 46 to the filter housing 26 is notcritical and can vary from that shown and described, the type ofconnection does impact the manner in which the conductive material 23 ofthe second portion 51 and pins 60, 62 of the first portion 49 areeffectively aligned when the qualified filter element 24 is installed inthe filter housing 26. This will be discussed further herein below withreference to FIGS. 9A-9F.

Referring to FIGS. 1 and 2, in use, when there is no water present inthe filter housing 26 and when the qualified filter element 24 is notinstalled in the filter housing 26, an open circuit across the pins 60,6 will be detected by the control circuit 50. That is, electricalcurrent that is applied to the WIF circuit 48 will not completely flowthrough pins 60, 62 and back to the control circuit 50 because the pins60, 62 are not electrically connected to each other. When such an opencircuit is detected, the control circuit 50 is programmed to control theoutput device 57 to indicate that there is no water in the filterhousing 26 and that the qualified filter element 24 is not installed inthe filter housing 26. If there is water inside the filter housing 26that rises to a level such that both ends 68 of first and second pins60, 62 are submerged in the water, a relatively low resistance acrossthe pins 60, 62 will be detected by the control circuit 50 because ofthe relatively high conductivity of the water. That is, the waterelectrically connects the ends 68 of the first and second pins 60, 62and it also provides a low level of resistance to current flow. Thecontrol circuit 50 is programmed to monitor the total resistance acrossthe pins 60, 62 and to compare this resistance with one or moreresistance values stored in the memory 58. The resistance values can forexample be stored in the memory in the form of a lookup table or otherlist that corresponds known resistance values to conditions of the WIFsensor 46. The memory 58 has a stored resistance value that correspondsto a situation where the ends 68 of the pins 60, 62 are submerged inwater. When a resistance in the WIF circuit 48 is identified by thecontrol circuit 50 that corresponds to this stored resistance value, thecontrol circuit 50 is programmed to communicate with and control theoutput device 57 via the communication link 53 to indicate that there iswater in the filter housing 26.

Similarly, the resistance of the WIF sensor 46 will also change when thequalified filter element 24 is installed in the filter housing 26 suchthat the ends 68 of the first and second pins 60, 62 are connected bythe conductive material 23. Electric current from the control circuit 50will flow across the first and second pins 60, 62 via the conductivematerial 23. The conductive material 23 will provide a certainresistance to the flow of current across the pins 60, 62. The controlcircuit 50 is programmed to monitor the resistance across the pins 60,62 and to compare this resistance with one or more resistance valuesstored in the memory 58. In one example, when the control circuit 50identifies any current flow across the pins 60, 62 whatsoever, thecontrol circuit 50 is programmed to control the output device 57 toindicate that the qualified filter element 24 is installed in the filterhousing 26 or that there is water in the filter housing 26. In anotherexample, the memory 58 has a stored resistance value in a lookup tableor other list that corresponds to the condition where the qualifiedfilter element 24 is installed in the filter housing 26. When aresistance in the WIF sensor 48 is identified by the control circuit 50that corresponds to this stored resistance value, the control circuit 50is programmed to control the output device 57 to indicate that thequalified filter element 24 is installed in the filter housing 26.

As discussed herein above, the configuration of the WIF circuit 48 canvary. FIG. 3A depicts another example wherein the WIF sensor 46 includesa resistor 78 that extends between and electrically connects the firstand second pins 60, 62. Similar to the example in FIG. 2, the controlcircuit 50 applies an electrical current to the noted first and secondpins 60, 62, which are connected by the resistor 78. If the qualifiedfilter element 24 is not installed in the filter housing 26 and there isno water in the filter housing 26, the electrical current will encountera known or predictable resistance provided by the resistor 78. Thecontrol circuit 50 is programmed to monitor the resistance across thepins 60, 62 and to compare the monitored resistance with one or moreresistance values stored in the memory 58. The memory 58 has a storedresistance value that corresponds to the situation where the qualifiedfilter element 24 is not installed in the filter housing 26 and there isno water in the filter housing 26 and the known resistance is providedby the resistor 78. When a resistance in the WIF sensor 48 is identifiedby the control circuit 50 that corresponds to this stored resistancevalue, the control circuit 50 is programmed to control the output device57 to indicate that the qualified filter element 24 is not installed inthe filter housing 26 and there is no water in the filter housing 26.

When the filter element 24 is not installed in the filter housing 26 andthere is water in the filter housing 26 that electrically connects theends 68 of the first and second pins 60, 62, some electrical currentwill flow across the ends 68 of the pins 60, 62 because water willtypically provide less resistance to the current than the resistanceprovided by the resistor 78. In some examples, some of the electricalcurrent still could also flow across the resistor 78. The relativeamounts of current flow across the pins 60, 62 and the resistor 78 willdepend upon the resistance provided by each. The control circuit 50 isprogrammed to monitor the total resistance across the pins 60, 62 and tocompare this resistance with one or more resistance values stored in thememory 58. The memory 58 has a stored resistance value that correspondsto the situation where the pins 60, 62 are submerged in water. When aresistance in the WIF sensor 48 is identified by the control circuit 50that corresponds to this stored resistance value, the control circuit 50is programmed to control the output device 57 to indicate that there iswater in the filter housing 26.

When the qualified filter element 24 is installed in the filter housing26, the ends 68 of the first and second pins 60, 62 are connected by theconductive material 23, and the conductive material 23 will provide acertain resistance to the flow of current across the pins 60, 62, whichtypically will be less than the resistance provided by resistor 78. Therelative amounts of current flow across the pins 60, 62 and the resistor78 will depend upon the resistance provided by each. Again, the controlcircuit 50 is programmed to monitor the resistance across the pins 60,62 and to compare this resistance with one or more resistance valuesstored in the memory 58. The memory 58 has a stored resistance valuethat corresponds to the situation where the qualified filter element 24is installed in the fitter housing 26 and current flows across theconductive material 23, and optionally also the resistor 78. When aresistance in the WIF sensor 48 is identified b the control circuit 50that corresponds to this stored resistance value, the control circuit 50is programmed to control the output device 57 to indicate that thequalified filter element 24 is installed in the filter housing 26.

FIG. 4 depicts another example of a WIF sensor 46. In this example, thefirst portion 49 of the WIF circuit 48 has three pins 60, 62, 80. Pins60 and 62 have ends 68 that extend into the filter housing 26. Pins 60and 80 have ends 70 that extend out of the filter housing 26. The pins62 and 80 are connected by a resistor 78. When a qualified filterelement 24 is not installed and the pins 60, 62 are not in water, nocurrent will flow through the WIF sensor 46. The control circuit 50 willsense an open circuit and will control the output device 57 to indicatethis condition, as discussed in the example of FIGS. 1 and 2. When aqualified filter element 24 is installed in the filter housing 26, theconductive material 23 on the bottom end cap 30 electrically connectsthe ends 68 of the pins 60, 62, thus connecting the first and secondportions 49, 51 of the noted WIF circuit 48. Electrical current willflow across the ends 68 of the pins 60, 62 via the conductive material23 and across the resistor 78 connecting the pins 62, 80. The totalresistance provided by the conductive material 23 and the resistor 78will be detected by the control circuit 50. The control circuit 50 isprogrammed to monitor the resistance across the pins 60, 62, 80 and tocompare this resistance with one or more resistance values stored in thememory 58. The memory 58 has a stored resistance value that correspondsto the situation where the qualified filter element 24 is installed inthe filter housing 26. When a resistance in the WIF circuit 48 isidentified by the control circuit 50 that corresponds to this storedresistance value, the control circuit 50 is programmed to control theoutput device 57 to indicate that the qualified filter element 24 isinstalled in the filter housing 26.

Also, once there is water inside the filter housing 26 that rises to alevel such that the first and second pins 60, 62 are submerged in thewater, a relatively tow resistance across the pins 60, 62 will bedetected by the control circuit 50 because of the relatively highconductivity of the water. That is, the water electrically connects theends 68 of the first and second pins 60, 62 and also provides someresistance to current flow through the pins 60, 62; however thisresistance will typically be less than the resistance provided by theconductive material 23 and the resistor 78. The control circuit 50 isprogrammed to monitor the resistance across the pins 60, 62 and tocompare this resistance with one or more resistance values stored in thememory 58. The memory 58 has a stored resistance value that correspondsto the situation where the pins 60, 62 are submerged in water. When aresistance in the WIF circuit 48 is identified by the control circuit 50that corresponds to this stored resistance value, the control circuit 50is programmed to control the output device 57 to indicate that there iswater in the filter housing 26.

As discussed herein above, the construction and orientation of thesecond portion 51 of the WIF circuit 48 can vary. In one example, withreference to FIG. 5A, the conductive material 23 forms a pair ofconcentric conductive rings 72, 74 that are circumferentially disposedaround the bottom end cap 30. The concentric conductive rings 72, 74 areconnected together by a radially extending conductive junction 76. Theconcentric conductive rings 72, 74 and the pins 60, 62 of the WIF sensor46 are both oriented and equally spaced apart such that when thequalified filter element 24 is properly installed in the filter housing26, the concentric conductive rings 72, 74 are aligned with and engagewith the ends 68 of the contacts or pins 60, 62, to thereby join thefirst and second portions 49, 51 and complete the WIF circuit 48. Thisconfiguration for the second portion Si alternatively can be applied incombination with any of the configurations for the first portion 49shown in FIGS. 1-4. Also, the conductive material 23 does not have to beformed into a concentric ring shape and does not have to becircumferentially aligned around the bottom end cap 30, as will beapparent from other examples in the following drawing figures.

The example shown in FIG. 5B is like the example of FIG. 5A, except thatit includes a resistor 82 instead of the radially extending conductivejunction 76. Resistor 82 is located with the second portion 51 andelectrically connecting to the concentric conductive rings 72, 74. Thisconfiguration for the second portion 51 alternately can be applied incombination with any of the configurations shown in FIGS. 1-4. When theconfiguration of FIG. 5B is used in combination with the configurationsof FIG. 3A and FIG. 4, the WIF circuit 48 will include two resistors 78,82 that are electrically connected in parallel when qualified filterelement 24 is installed and the first portion and second portion 49, 51are joined together. Resistor 78 is located with the first portion 49and resistor 82 is located with the second portion 51.

FIG. 6A depicts another example of the second portion 49 on bottom endcap 30, wherein the conductive material 23 includes a bifurcatednon-circumferential conductive ring 88 for connecting the ends 68 of thefirst and second pins 60, 62 when the qualified filter element 24 isinstalled in the filter housing 26. The diameter of thenon-circumferential conductive ring 88 is substantially the same as thedistance between the first and second pins 60, 62 to assist the notedconnection. A resistor 82 is located with the second portion andelectrically connects two halves 88 a, 88 b of the non-circumferentialring 88. This configuration for the second portion 51 alternately can beapplied in combination with any of the configurations shown in FIGS.1-4. When the configuration of FIG. 6A is used in combination witheither of the configurations of FIG. 3A or FIG. 4, the WIF circuit 48will include two resistors 78, 82 in series when qualified filterelement 24 is installed and the first portion and second portion 49, 51are joined together. Resistor 78 is located with the first portion 49and resistor 82 is located with the second portion 51.

FIG. 613 is an example like FIG. 6A, except the circumferentialconductive ring 88 is a complete circle that is molded into the bottomend cap 30 and thus does not require the noted resistor 82 or anothertype of junction.

FIGS. 7A-7D depict some of the many potential combinations andconfigurations of the noted first and second portions 49, 51 of the WIFcircuit 48. In FIG. 7A, the bottom end cap 30 is entirely for at leastpartly) formed of conductive material 23 such that the bottom end cap 30itself forms the noted second portion 51 for completing the WIF circuit48. Installation of the qualified filter element 24 in the filterhousing 26 causes the ends 68 of the first and second pins 60, 62 tocontact the bottom end cap 30, thus completing the noted WIF circuit 48.This configuration for the second portion 51 can be applied incombination with any of the configurations shown in FIGS. 1-4.

FIG. 7B depicts a combination of the WIF sensor 46 and end cap 30 shownin FIGS. 3A and 5B, respectively, as described herein above.

FIG. 7C, depicts a combination of the WIF sensor 46 and end cap 30 shownin FIGS. 2 and 5B, respectively, as described herein above.

FIG. 7D depicts a combination of the WIF sensor 46 and end cap 30 shownin FIGS. 4 and 5A, respectively, as described herein above.

FIGS. 8A and 8B depict examples wherein the first and second portions ofthe WIF circuit 48 are connected together by an intermediate conductiveelement 90 when the qualified filter element 24 is installed in thefilter housing 26. These examples illustrate that the first and secondportions 49, 51 do not have to be directly connected together, butinstead can be connected by an intermediate conductive device. In FIG.8A, the conductive element 90 includes part of the filter housing 26,and particularly a conductive metal casing 92 that connects the firstpin 60 to the bottom end cap 30. In this example, the bottom end cap 30can be like the example in FIG. 7A, wherein all of or at least part ofthe bottom end cap 30 is formed of conductive material 23 and itselfprovides the second portion 51 of the WIF circuit 48. The conductivemetal casing 92 is on an interior surface 94 of the filter housing 26and is connected to the pin 60. The conductive casing 92 lines theinterior of the base receptacle 34 and extends upwardly therein. Atleast the top end 115 of the conductive metal casing 92 engages with theconductive material 23 on the end cap 30 when the qualified filterelement 24 is installed in the filter housing 26. The end 68 of the pin62 also connects to conductive material 23, thus connecting the firstand second portions 49, 51 of the WIF circuit 48, which functions likethe example shown in FIG. 4.

In FIG. 8B the conductive element 90 includes a conductive metal casing96 on the centerpost 44 of the filter housing 26. The conductive metalcasing 96 connects the second and third pins 62, 80 to the conductivematerial 23 on the bottom end cap 30 when the qualified filter element24 is properly installed in the filter housing 26. This completes theWIF circuit 48, which functions like the example shown in FIG. 4.

Through research and experimentation, the present inventors have alsofound that it is desirable that the radial orientation of the notedfirst and second portions 49, 51 of the WIF circuit 48 are automaticallyor easily aligned during installation such that the noted electricalconnection is made between the first and second portions 49, 51 when thequalified filter element 24 is inserted in the filter housing 26. Thus,in the illustrated examples, it is desirable that the ends 68 of thefirst and second pins 60, 62 become aligned with the conductive element23 of the qualified filter element 24 once the qualified filter element24 is properly installed. FIGS. 9A-9F depict some of the combinationsthat can achieve this objective.

In FIG. 9A, the WIF sensor 46 is either locked to or formed as a part ofthe filter housing 26, such that the WIF sensor 46 cannot be rotatedwith respect to the filter housing 26. One example of this type of WIFsensor 46 is shown in FIG. 313. The bottom end cap 30 is like theexample shown in FIG. 7A, wherein a portion of or the entire bottom endcap 30 is made of conductive material 23 and thus itself provides thesecond portion 51 of the WIF circuit 48. In addition, the bottom end cap30 is provided with radially concentric, circumferential grooves 84, 86for receiving and engaging with the ends 68, 70 of the first and secondpins 60, 62. The circumferential grooves 84, 86 are electricallyconnected by a radial junction groove 85. The bottom end cap 30 can beset at any rotational position with respect to the WIF sensor 46,because the entire circumference of the grooves 84, 86 consistentlyallows for electrical contact between the noted first and secondportions 49, 51.

In FIG. 9B, the bottom end cap 30 is like the example shown in FIG. 7A,wherein a portion of or the entire bottom end cap 30 is made ofconductive material 23 and thus itself provides the second portion 51 ofthe WIF circuit 48. In addition, the bottom end cap 30 is provided witha non-circumferential, circular conductive groove 93. A mechanical lock99 is provided to retain the bottom end cap 30 such that thenon-circumferential conductive groove 93 remains at a fixedcircumferential position with respect to the WIF sensor 46. The type ofmechanical lock can widely vary, some examples are disclosed withrespect to FIGS. 10A and 10B, described herein below. The body 66 of theWIF sensor 46 is connected to the filter housing 26 by the threadedconnection 42, such that the body 66 is radially rotatable with respectto the filter housing 26. The circular shape and the fixedcircumferential position of the conductive groove 93 ensures properelectrical connection between the ends 68 of the first and second pins60, 62 regardless of the radial orientation of the body 66 of the WIFsensor 46 with respect to the filter housing 26. The mechanical lock 99ensures that the conductive groove 93 is aligned with the ends 68 of thefirst and second pins 60, 62.

In FIG. 9C, the bottom end cap 30 is like the example shown in FIG. 7Awherein at least a portion of the bottom end cap 30 is made ofconductive material 23 and thus itself provides the second portion 51 ofthe WIF circuit 48. In hu addition, the bottom end cap 30 is providedwith the non-circumferential, circular conductive groove 93 formedtherein. The WIF sensor 46 is like the example shown in FIG. 3B, whereinthe body 66 of the WIF sensor 46 is locked with or formed into thefilter housing 26. The mechanical lock 99 locks the rotationalorientation of the bottom end cap 30 with respect to the filter housing26.

FIG. 9D depicts another example, wherein the bottom end cap 30 is likethe example shown in FIG. 5A and the WIF sensor 46 is like the exampleshown in FIG. 3B. The body 66 of the WIF sensor 46 is locked with or apart of the filter housing 26. The concentric circumferential nature ofthe conductive rings 72, 74 ensure that connection between the first andsecond portions 49, 51 of the WIF circuit 48 occurs when the qualifiedfilter element 24 is installed in the filter housing 26, regardless ofthe rotational position of the qualified filter element 24 with respectto the fixed WIF sensor 46.

FIG. 9E is like FIG. 9D except instead of the circumferential concentricconductive rings 72, 74, the bottom end cap 30 is provided with thecircular, non-circumferential conductive ring 88. The mechanical lock 99locks the rotational orientation of the bottom end cap 30 with respectto the filter housing 26. The body 66 of the WIF sensor 46 is lockedwith or a part of the filter housing 26. Thus the circumferentialorientation of the non-circumferential conductive rings 87, 88 isaligned with the circumferential orientation of the WIF sensor 46 whenthe qualified filter element 24 is installed in the filter housing 26.

FIG. 9F depicts another example wherein the bottom end cap 30 is likethe example in FIG. 7A and the first portion 49 of the WIF circuit 48 islike the example in FIG. 2. At least part of the bottom end cap 30 ismade of conductive material 23 such that the circumferential alignmentof the respective first and second portions 49, 51 is accomplished whenthe qualified filter element 24 is installed in the filter housing 26.

FIGS. 10A and 10B show some examples of mechanical locks 99 for lockingthe first and second portions 49, 51 of the WIF circuit 48 together.FIG. 10A depicts an example wherein a pin 98 is biased by a spring 101to engage with a corresponding concave conductive ring 100 on the bottomend cap 30. The spring 101 is disposed on one of the pins 60, 62, 80 ofthe WIF sensor 46. The pin 98 has a head that 103 that engages thespring 101. The base of a bracket 105 engages the opposite side of thespring 101. Insertion of the qualified filter element 24 into the fitterhousing 26 moves the bottom end cap 30 towards the pins 60, 62 andoptionally 80 of the WIF sensor 46, thus causing the concave conductivering 100 to engage with the head 105 of pin 98. This compresses thespring 101 until the pin 98 contacts the pin 60, 62, 80, thus forming anelectrical connection and completing the WIF circuit 48. FIG. 10Bdepicts an example of an end cap 30 for use with the assembly of FIG.10A, wherein the concave conductive ring 100 is in the form of aconductive groove 113 formed in the bottom end cap 30.

FIGS. 11A-11B depict another example of a fitter assembly 200 having aqualified filter element 202 and a filter housing 204 for the qualifiedfilter element 202. At least one magnetic element 206 is disposed on thequalified filter element 202. The magnetic element 206 has a magneticfield 208 and can be a magnet or any other type of magnetic element. Apair of wires 210 are disposed on the filter housing 204. A controlcircuit 212 having a programmable processor 214 and memory 216 iselectrically coupled to the wires 210 so as to monitor a current acrossthe wires 210. In this example, the qualified filter element 202 is acylindrical filter element having a circumferential outer surface 218.The magnetic element 206 is on the circumferential outer surface 218.The qualified filter element 202 can be installed in the filter housing204 by rotating the qualified filter element 202 clockwise so that themagnetic element 206 passes by the plurality of wires 210 during therotations. The qualified filter element 202 can be uninstalled in thefilter housing 204 by rotating the qualified filter element 202counterclockwise so that the magnetic element 206 passes by theplurality of wires 210 during the rotations.

Like the example in FIG. 1, the programmable processor 214 can becommunicatively connected to a computer readable medium that includesvolatile or nonvolatile memory upon which computer readable medium isstored. The programmable processor 214 can access the computer readablemedium and upon executing the computer readable code carries out thefunctions as described herein. The control circuit 212 can be anysuitable control device for interpreting information from the wires 210,but is not limited to an engine control module (ECM.), a controller, afluid management control module, or any suitable data/informationprocessing device, which may employ one or more software routines, asappropriate. In this example, the control circuit 212 is powered by anyconventional power source, such as for example one or more batteries 63.The control circuit 212 is configured to supply an electrical current tothe pair of wires 210 and to receive electrical current from the pairwires 210. However the control circuit 212 does not have to supplyelectrical current to the pair of wires 210; rather the noted electricalcurrent could be directly provided by any other power source such abattery.

In use, when the qualified filter element 202 is installed in the filterhousing 204, the plurality of wires 210 cuts the magnetic field 208 ofthe magnetic element 206 thereby modifying a current generated acrossthe wires 210. The current on the wires 210 is monitored by the controlcircuit 212. A change in the current on the wires 210 alerts the controlcircuit 212 that the qualified filter element 202 is installed. Like theexample in FIG. 1, the control circuit 212 can be programmed to controlan output device 57 having warning lights 59, 61 and/or otherconventional means for alerting an operator as to whether there is aqualified filter element 24 installed in the filter housing 26.

FIGS. 11C-11D depict another example of a filter system 220 wherein aplurality of magnetic elements 206 are spaced apart on thecircumferential surface. The control circuit 50 has a plurality of inputterminals A-D that are connected to respective pairs of wires 210. Theorientation and location of the respective magnetic elements in theplurality 206 can be selected so that movement of the qualified filterelement 202 with respect to the filter housing 204 (e,g, rotation duringinstallation of the qualified filter element 202 into the filter housing24) causes a current induced pulse that is detected by the controlcircuit 212 via the input terminals A-D. The control circuit 212 can beprogrammed to interpret the current induced pulse as a code and tocompare the current induced pulse or code to a stored current inducedpulse or code in the memory 216 to thereby verify that the filterelement is a qualified filter element 202. The code can vary dependingupon the location and orientation of the magnetic elements 206 in theplurality. In the example shown, the qualified filter element 202 isturned clockwise during installation. This causes terminals A and B togenerate a negative current signal that is read by the control circuit212. Terminals C and D generate a positive current signal that is readby the control circuit 212. The memory 216 of the control circuit 212contains a look-up table or other list that indicates that when thiscode or combination of positive and negative current signals aredetected, the control circuit 212 should indicate via, the output device57 that a qualified filter element 202 has been installed. The controlcircuit 212 will not indicate that a qualified filter element 202 hasbeen installed until this particular combination of positive andnegative current signals are detected. Conversely, when the qualifiedfilter element 202 is uninstalled, counterclockwise rotation of thequalified filter element 202 with respect to the filter housing 204causes terminals A and B to generate a positive current signal andterminals C and D generate a negative current signal. Again, the memory216 of the control circuit 212 contains a look-up table or other listthat indicates that when this combination of positive and negativecurrent signals are detected, the control circuit 212 should indicatevia the output device 57 that a qualified filter element 202 has beenuninstalled.

Changing the location or orientation of the magnetic element 206 willchange the corresponding current-induced pulse and thus change the codethat is interpreted by the control circuit 212, allowing themanufacturer to tailor the noted code to thereby prevent counterfeiting.

Although only a few example examples have been described in detailabove, those skilled in the art will readily appreciate that manymodifications are possible in the example examples without materiallydeparting from this invention. Accordingly, all such modifications areintended to be included within the scope of this disclosure as definedin the following claims. In the claims, means plus function clauses areintended to cover the structures described herein as performing therecited function and not only structural equivalents but also equivalentstructures. Thus, although a nail and a screw may not be structuralequivalents in that a nail employs a cylindrical surface to securewooden parts together, whereas a screw employs a helical surface, in theenvironment of fastening wooden parts, a nail and a screw may beequivalent structures. It is the express intention of the inventors notto invoke 35 U.S.C. §112, paragraph six, for any limitations of any ofthe claims herein, except for those in which the claim expressly usesthe words “means for” together with an associated function.

What is claimed is:
 1. A filter assembly, comprising: a qualified filterelement that filters fuel; a filter housing for the qualified filterelement; and a water-in-fuel sensor that senses presence of water in thefilter housing, wherein an electrical resistance of the water-in-fuelsensor changes based upon whether the qualified filter element isinstalled in the housing.
 2. The assembly according to claim 1, whereinthe water-in-fuel sensor comprises an electrical circuit having a firstportion located with the housing and a second portion located with thequalified filter element, wherein installing the qualified filterelement in the housing electrically connects the second and firstportions of the electrical circuit.
 3. The assembly according to claim2, wherein the first portion of the electrical circuit comprises firstand second electrical contacts.
 4. The assembly according to claim 3,comprising a resistor that electrically connects the first and secondelectrical contacts.
 5. The assembly according to claim 4, wherein thefirst and second electrical contacts and the resistor are located withthe first portion.
 6. The assembly according to claim 4, comprising asecond resistor located with the second portion, wherein the secondresistor electrically connects the first and second electrical contacts.7. The assembly according to claim 4, wherein the resistor is locatedwith the second portion.
 8. The assembly according to claim 3, whereinthe circuit further comprises a third electrical contact, and comprisinga resistor that electrically connects the second and third electricalcontacts.
 9. The assembly according to claim 3, wherein the filtercomprises an end cap and wherein the second portion of the circuit islocated with the end cap.
 10. The assembly according to claim 9, whereinthe end cap comprises conductive material that electrically connects thefirst and second electrical contacts when the qualified titter elementis installed in the filter housing.
 11. The assembly according to claim10, wherein the end cap is made of the conductive material.
 12. Theassembly according to claim 11, comprising grooves in the cap forreceiving the first and second electrical contacts.
 13. The assemblyaccording to claim 10, wherein the conductive material comprisesconductive rings that are circumferentially disposed around the end cap,wherein the conductive rings electrically connect the first and secondelectrical contacts when the qualified filter element is installed inthe filter housing.
 14. The assembly according to claim 10, wherein theconductive material comprises at least one non circumferentialconductive ring that is disposed on the end cap, wherein thenon-circumferential conductive ring electrically connects the first andsecond electrical contacts when the qualified filter element isinstalled in the filter housing.
 15. The assembly according to claim 3,comprising a mechanical lock retaining at least one of the first andsecond portions of the electrical circuit at a circumferential locationwith respect to the other of the first and second portions of theelectrical circuit.
 16. The assembly according to claim 15, wherein themechanical lock comprises a spring-biased pin that engages with one ofthe first and second portions of the electrical circuit.
 17. Theassembly according to claim 2, comprising a conductive elementconnecting the first portion of the electrical circuit with the secondportion of the electrical circuit when the qualified filter element isinstalled in the housing.
 18. The assembly according to claim 17,wherein the conductive element comprises a casing on an interior surfaceof the filter housing.
 19. The assembly according to claim 17, whereinthe conductive element comprises a casing on a centerpost of the filterhousing.
 20. The assembly according to claim 2, comprising a threadedconnection between a body of the water in-fuel sensor and the housing.21. The assembly according to claim 2, wherein the water-in-fuel sensoris formed as a part of the housing.
 22. A filter system, comprising aqualified filter element that filters fuel; a filter housing for thequalified filter element; a water-in-fuel sensor that senses presence ofwater in the fuel; and a control circuit that determines whether thereis water in the filter housing based upon an electrical resistance ofthe water-in-fuel sensor, the control circuit being electricallyconnected to the water-in-fuel sensor; wherein the control circuit alsodetermines whether the qualified filter element is installed in thehousing based upon the electrical resistance of the water-in-fuelsensor.
 23. The filter system according to claim 22, wherein the controlcircuit has a memory that has a stored electrical resistance value thatindicates the presence of water in the filter housing and a storedelectrical resistance value that indicates when the qualified filterelement is installed in the housing, and wherein the control circuitcompares the electrical resistance of the water-in-fuel sensor to thestored electrical resistance values to determine whether there is waterin the filter housing and whether the qualified filter element isinstalled in the housing.
 24. The filter system according to claim 23,wherein the at least one stored electrical resistance value thatindicates whether the qualified filter element is installed in thehousing comprises an open circuit resistance value.
 25. A method ofidentifying a qualified filter element in a filter assembly having afilter housing, the method comprising: providing a water-in-fuel sensorhaving an electrical circuit comprising a first portion located with thehousing and a second portion located with the qualified filter element;inserting the qualified filter element into the filter housing; sensingwith a control circuit a change in electrical resistance of thewater-in-fuel sensor; and indicating that the qualified filter elementis installed in the filter housing based on the change in electricalresistance.
 26. A filter assembly comprising: a filter housing; aqualified filter element; a plurality of magnetic elements disposed onat least one of the filter housing and the qualified filter element, theplurality of magnetic elements each having a magnetic field; a pluralityof wires disposed on at least the other of the filter housing and thequalified filter element; and a control circuit that is electricallycoupled to the plurality of wires and that detects an electrical currentin the plurality of wires; wherein when the qualified filter element isinstalled in the filter housing, the plurality of wires cuts themagnetic field of at least one of the plurality of magnetic elements andthereby changes the electrical current in the plurality of wires;wherein the control circuit determines that the qualified filter elementis installed in the filter housing based on a change in the electricalcurrent in the plurality of wires.
 27. The filter assembly according toclaim 26, wherein the current generated in the plurality of wiresproduces a current induced pulse and wherein the control circuitcompares the current-induced pulse to a stored current-induced pulse toverify whether the qualified filter element is qualified.
 28. The filterassembly according to claim 27, wherein changing the location of theplurality of magnetic elements on the filter housing changes thecurrent-induced pulse.
 29. The filter assembly according to claim 27,wherein changing the orientation of the plurality of magnetic elementson the filter housing changes the current-induced pulse.
 30. The filterassembly according to claim 26, wherein the qualified filter element hasa circumferential outer surface and wherein magnetic elements in theplurality of magnetic elements are spaced apart around thecircumferential outer surface.
 31. The filter assembly according toclaim 30, wherein the qualified filter element is installed in thefilter housing by rotating the qualified filter element with respect tothe filter housing so that the plurality of magnetic elements arerotated past the plurality of wires during installation.
 32. A method ofidentifying a qualified filter element in a filter assembly having afilter housing, the method comprising: providing a plurality of magneticelements on at least one of the qualified filter element and the filterhousing, the plurality of magnetic elements comprising a magnetic field;providing a plurality of wires on at least the other of the qualifiedfilter element and the filter housing; installing the qualified filterelement into the filter housing; sensing with a control circuit anelectrical current along the plurality of wires; and identifying withthe control circuit that the qualified filter element is installed inthe filter housing when the electrical current across the wires changes.33. The method according to claim 32, comprising rotating the qualifiedfilter element with respect to the filter housing so that the pluralityof magnetic elements passes by the plurality of wires during rotations.34. The method according to claim 33, comprising interpreting with thecontrol circuit a current induced pulse caused by the current generatedin the plurality of wires during said rotation and comparing the currentinduced pulse to a stored code to verify that the qualified filterelement is qualified.
 35. The method according to claim 34, comprisingchanging the location of the plurality of magnetic elements to changethe current induced pulse.
 36. The method according to claim 34,comprising changing the orientation of the plurality of magneticelements to change the current induced pulse.